Development of AlInN photoconductors deposited by sputtering

Abstract

In this work, we have developed photoconductor devices based on Al0.39In0.61N layers grown on sapphire by reac-tive radio-frequency magnetron sputtering. The fabricat-ed devices show a sublinear dependence of the photocur-rent as a function of the incident optical power. The above-the-band-gap responsivity reaches 7 W/A for an ir-radiance of 10 W/m2 (405 nm wavelength). The response decreases smoothly for below-the-bandgap excitation, dropping by more than an order of magnitude at 633 nm. The devices present persistent photoconductivity effects associated to carrier trapping at grain boundaries.